Controlled Large-Scale Tests of Practical Grounding Electrodes—Part II: Comparison of Analytical and Numerical Predictions With Experimental Results
Controlled Large-Scale Tests of Practical Grounding Electrodes—Part II: Comparison of Analytical and Numerical Predictions With Experimental Results
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实际接地电极的受控大规模试验——第二部分：分析预测和数值预测与实验结果的比较
DOI：
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发表时间：
2014
影响因子：
4.4
通讯作者：
A. Haddad
中科院分区：
文献类型：
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作者：
D. Clark;D. Guo;D. Lathi;N. Harid;H. Griffiths;A. Ainsley;A. Haddad
本文介绍了在户外实验设施进行的测试，在同伴第1部分的文件中描述，调查实际接地系统的性能。在这里，低压直流，交流和脉冲测试棒和栅电极上进行的结果进行了说明，并测量量与数值模型获得的计算值进行了比较。测量的接地电阻和阻抗在低频（包括电源频率）显示出合理的协议与简单的标准公式和计算模型，但揭示了一个显着的下降与电流大小的范围内，经常用于高压接地系统的实际测试。这可能会影响接地测试设备的规格，并将低压/低电流下的接地电阻/阻抗测量值外推至实际故障电流的代表值。还测量了接地阻抗的频率依赖性。具体而言，接地模型中通常不考虑高达100 kHz的频率范围内的阻抗下降。
This paper presents tests carried out at an outdoor experimental facility, described in the companion Part 1 paper, to investigate the performance of practical grounding systems. Here, the results of low-voltage dc, ac, and impulse tests performed on rod and grid electrodes are described, and the measured quantities are compared with computed values obtained from numerical models. Measured ground resistance and impedance at low frequency (including power frequency) showed reasonable agreement with simple standard formulae and computational models, but revealed a significant falloff with current magnitude in the range often used for practical testing of high-voltage grounding systems. This may have implications for the specifications of grounding test equipment and extrapolation of measured ground resistance/impedance at low-voltage/current to values representative of realistic fault currents. A frequency dependence of ground impedance was also measured. Specifically, a fall in impedance over a frequency range up to 100 kHz is not generally accounted for in grounding models.